Process of mining sulfur.



ANTHONY F. LUCAS AND GODFREY M. S. TAI'I, OF WASHINGTON, DISTRICT OF COLUMBIA;

onrio.

SAID TAIT ASSIGNOR TO SAID LUCAS.

PROCESS OF MINING SULFUR.

1 259,536. No Drawing To all whom it may concern:

Be it known that we, ANTHONY F. LUCAS and GODFREY M. S. TAIT, citizens of the United States, and residents of lVashington, in the District of Columbia, have invented certain new and useful Improvements in Processes of Mining Sulfur, of which the following is a specification.

This invention relates to the mining of sulfur occurring,as subterranean deposits,

- by melting the sulfurand forcing the molten mass to the surface; and it consists essentially in generating the heat required to melt the sulfur by the controlled oxidation of partof the sulfur deposit.

According to present methods of operation it is customary to force large quantities of steam or water at a high temperature and pressure into the sulfur well to melt the sulfur deposit and force the melted sulfur to the surface. One of the great disadvantages of this method is its low efiiciency due to the loss of heat and the necessity of generating large quantities of steam at high pressure. By the present process the heat is generated in the masswhich is to be melted so that the efiieiency is relatively high and the expense of generating large quantities of steam is entirely avoided.

In carrying out the process a well is drilled into the sulfur bearing strata or deposit in the usual manner and the sulfur ignited either by electricity or some other suitablemeans and the ignited mass is subjected to a compressed gaseous mixture containing oxygen and an inert gas in such proportions that a restricted oxidation of the ignited sulfur is effected. If compressed air alone were used there would be an intense generation of heat in excess of that required to merely melt the sulfur, thereby rendering the molten sulfur viscid. It therefore becomes advantageous to premingle with the air or other oxidizing gas a sufiicient amount of an inert gas to control the oxidation and prevent undue heating and the conversion of all of the sulfur into its products of oxidation.

, The inert gas which we prefer to use is carbon dioxid, usually mixed with nitrogen, which may be readily obtained from the stack gases of the steam boiler plant used Specification of Letters Patent.

Patented Mar. 19, 1918.

Application filed December 27, 1916. Serial No. 139,193.

to generate the power to operate the air compressor; or in the event of using internal combustion engines to generate the power, the exhaust gases from these engines may be used.

The burning and melting of the sulfur occurs gradually'and continuously, the pressure of the gas mixture being such as to force the molten sulfur to the surface. The composition of the gas mixture used both for effecting a restricted combustion and for forcing the fluid mass to the surface may be varied to a considerable extent without departing from the scope of our invention.

We claim:

l. A process of mining subterranean sulfur deposits which comprises subjecting the sulfur to a controlled oxidation with a mixture of air and carbon dioxid under sufiicient pressure to force the resulting molten mass to the surface.

2. A process of mining subterranean sulfur deposits which comprises subjecting the ignited sulfur to a compressed gaseous mixture comprising oxygen and an inert gas in such proportions as to effect a restricted combustion of the sulfur, the gas pressure being sufficient to force the resulting molten mass to the surface.

3. A process of mining subterranean sul fur deposits which comprises igniting part of the sulfur,- and subjecting the ignited sulfur to a compressed gaseous mixture containing oxygen and carbon dioxid in such proportions as to efl'ect a restricted oxidation of the sulfur and generate sufiicient heat to melt further quantities of sulfur, the gas pressure being such as to force the molten mass to the surface.

4. In the working of subterranean sulfur deposits the steps which comprise ignit- ANTHONY F. LUCAS. GQDFREY M. S. TAIT. 

